Anthropometric measurements were performed by a neonatologist, who was aware of the infants' intervention assignment, using a pediatric scale for weight, a length board for length, and a tape measure for head circumference. Growth delay was defined as weight for length less than 5th percentile at one year adjusted age. At 1 year follow-up, a research assistant reviewed each child's clinic chart and noted whether any of the following health conditions or receipt of health-services: cerebral palsy, blindness, hearing impairment, seizure disorder, oxygen requirement, need for tracheostomy tube and ventriculo-peritoneal shunt.